QTECH SmartEdge 600 Configuration - Manual (Page 11)

Overview
1.4 AAA Route Download Overview
The router allows you to configure and advertise IPv4 access routes before the
routes have been assigned to subscribers. Pre-provisioning access routes
helps eliminate routing protocol scalability issues or delays when the protocol
is converging or when a large number of subscribers is being simultaneously
activated. More than one RADIUS server can be designated as a route
download server. While defining a route download server, RADIUS server
redundancy operates in the normal way.
When this feature is enabled, the router periodically sends a RADIUS
Access-Request message to the RADIUS server acting as a route download
server, requesting to download routes. To respond, the RADIUS server sends
an Access-Accept message containing a set of routes within the RFC-specified
RADIUS packet length, which the router downloads. The router repeats the
request until all the routes have been downloaded; the RADIUS server signals
completion by rejecting the Access-Request message. Once all the routes
have been downloaded successfully, the router installs the access routes in its
RIB. If the download fails at any point, all the routes are discarded; the router
never installs an incomplete batch of routes into its RIB.
A set of download requests is sent on a periodic basis, beginning at a
configured time of day and repeating at configured intervals thereafter. Routes
are carried in the Framed-Route attribute (standard attribute 22), which must
be formatted as specified in RFC 2865, RADIUS. The metric field in the
Framed-Route attribute is optional. The router uses the Context-Name attribute
(VSA attribute 4) to identify the context where the route is downloaded.
This feature assumes that the routes downloaded from the RADIUS route
download server have a more specific prefix than the prefix of the subscriber
route. The router does not check for configuration errors in this regard.
7 61/1543-CRA 119 1170/1 Uen L | 2012-12-04